Automatic systems and devices which answer telephones and provide pre-recorded or automatically generated information to callers have become very common. Generally, these systems provide the caller with one or more informational messages, which the caller then bases some future action upon. Some systems also initiate the call, and it is the called party that is provided the pre-recorded or automatically generated information.
Typical examples of such systems are: voice menus, which provide callers with a set of choices, from which the caller then selects the most appropriate choice; and automatic call answering, which plays a pre-recorded message from the called party, and then allows the calling party to record a message.
All of the above systems are well known. Northern Telecom manufacturers a number of systems which will answer an inbound call, provide the caller with outbound messages, and then allow the caller to take further action (e.g. Meridian IVR, Flashtalk automated attendant for Norstar, and Meridian Mail's automated attendant and voice services); most of these systems also are capable of initiating calls and providing the called party with information. Northern Telecom also manufactures a variety of systems and devices to provide call answering, ranging from those designed to answer a single private line (e.g. Nortel 9516 digital answering machine) to those designed for a key system (e.g. Flashtalk for Norstar) to those designed for a PBX or even a central office (e.g. Meridian Mail).
These systems generally allow callers to take actions while the outbound instructions or messages are being played, before they have been heard in their entirety by the calling party. This is an important function of such systems as it facilitates interaction with the system by frequent users, who, having heard the outbound message once, do not need or desire to hear it again.
However, a problem occurs when the calling party takes such an action prior to the completion of the playing of the outbound message, when the outbound message has changed since the caller last heard it such that the calling party would, if they heard the message in its entirety, take a different action. In general, this results in the calling party missing valuable information, or taking inappropriate action, or missing the opportunity to take an action that would save them time and or money.
Within the domain of call answering systems or devices, this problem can result in callers missing an important part of the greeting and leaving a message anyway. For example, they may not hear that the called party is out of the office for the next 6 months, won't be retrieving messages until then, and that they should contact a third party instead. The impact of this missed greeting varies with the call, but in some business environments such miscommunications may lead to significant expenses or lost revenues.
This problem is typically addressed, if at all, in one of the following ways: the outbound message is made uninterruptible, forcing all callers to hear it in its entirety; the outbound message is prefixed with an uninterruptible warning that the message has changed; or the outbound message is prefixed with an interruptible warning that the message has changed.
Each of these typical solutions to this problem cause other problems.
When the outbound message is completely uninterruptible, repeat callers are forced to spend their time and possibly toll charges, and the system itself forced to spend its resources, playing a message which has already been heard.
When an uninterruptible prefix is added to a message, first-time callers are forced to spend their time and possibly additional toll charges listening to a warning prefix that they don't even need, and repeat callers are still forced to waste time and possibly money on listening to the warning they have already heard, and the system itself must waste resource playing the warning to both types of callers.
When an interruptible prefix is added to a message, first-time callers are forced to spend their time and possibly additional toll charges listening to a warning prefix that they don't even need, and the system must spend its resources playing it, and repeat callers may miss the warning completely in their haste to skip on to the response.